1850 Census
Ferguson     Alexander       39  KY      IN      Jennings; Geneva
Ferguson     Hannah          18  IN      IN      Jennings; Geneva
Ferguson     John            9   IN      IN      Jennings; Geneva
Ferguson     Margaret        16  IN      IN      Jennings; Geneva
Ferguson     Mary A          1   IN      IN      Jennings; Geneva
Ferguson     Milla           12  IN      IN      Jennings; Geneva
Ferguson     Nancy           39  KY      IN      Jennings; Geneva
Ferguson     Nathaniel       7   IN      IN      Jennings; Geneva
Ferguson     William         14  IN      IN      Jennings; Geneva
Ferguson     Christena       10  IN      IN      Jennings; Sandcreek
1860 Census
Forgerson    John            19  Male    In     IN      Jennings Geneva Twp
Forgerson    William         24  Male    In     IN      Jennings Geneva Twp
Ferguson     William         42  Male    Oh     IN      Jennings Montgomery Twp
Ferguson     Thomas          38  Male    Oh     IN      Jennings Vernon Twp
1870 Census
Furguson     Mary            60  Female  Irel   IN      Jennings Center Twp
Ferguson     John A          24  Male    Oh     IN      Jennings Geneva Twp
Ferguson     Daniel          53  Male    Va     IN      Jennings Montgomery Twp
Ferguson     Thomas          50  Male    Oh     IN      Jennings Montgomery Twp
Ferguson     William         54  Male    Oh     IN      Jennings Montgomery Twp
Ferguson     Mary            34  Female  In     IN      Jennings Vernon Twp
1900 Census
Ferguson        Oliver E         35  Male    In      IN      Jennings Lovett Twp
Farguson        William H        45  Male    In      IN      Jennings Lovett Twp
1910 Census
Ferguson        James R          47  Male    In      IN      Jennings Lovett Twp
Ferguson        William H        55  Male    In      IN      Jennings Lovett Twp
1920 Census
Ferguson        Allen            49  Male    In      IN      Jennings 3-Wd; N Vernon; Center Twp
Ferguson        Violet           13  Female  In      IN      Jennings Bigger Twp
Ferguson        J R              56  Male    In      IN      Jennings South Twp
Ferguson        W H              67  Male    In      IN      Jennings South Twp

The 1830 Census was copied from two sources; Accelerated Indexing Systems International, Inc and the INDIANA Historical Society.  Many spellings of the FERGUSON surname and different numbers, one may be the page number of  the census and one may be the household number.  As this is an index, the original census should be consulted.

IN 1830-Jennings Co
FURGUSON            WILLIAM                     JENN              157
FERGUSON            WILLIAM                     JENN              323

IN - 1840 Census - Jennings Co
Information from the IN Historical Society
FURGERSON           Isaac          Jenn                489
FERGERSON           Alexander      Jenn                451